European aurochs DNA in domestic cattle

A study  ((Edwards CJ et al., 2007. Mitochondrial DNA analysis shows a Near Eastern Neolithic origin for domestic cattle and no indication of domestication of European aurochs. Proceedings Royal Society B 274:1377-1385)) just published by the Royal Society sheds some light on the genetic relationship between the European auroch and modern European cattle breeds. Cattle were initially domesticated perhaps around 10,000 years ago in Mesopotamia, and independently in India and probably Africa. As animal agriculture spread into Europe from the Middle East, domesticated cattle must have coexisted with wild European aurochs for some time, since aurochs in Europe didn’t die out until much later (in fact, the last aurochs appear to have lived in Poland around 1627). Analysis of contemporary as well as ancient mitochondrial DNA from Middle Eastern and Central European archaeological sites now seems to suggest that European cattle originated solely from Middle Eastern aurochs, and that no introgression of European auroch genes into domesticated cattle occurred during their long coexistence.

However, an earlier study  ((Götherström A et al., 2005. Cattle domestication in the Near East was followed by hybridization with aurochs bulls in Europe. Proceedings Royal Society B 272:2345-2350)) did show that there had indeed been introgression of auroch Y chromosomes into Northern and Central European domestic cattle and that these Y chromosome markers still exist in some European breeds. Of course, what might seem contradictory really isn’t: mitochondria are strictly inherited from one’s mother, and the mating of domestic cows with auroch bulls wouldn’t have left any mitochondrial evidence. It would be interesting to know whether such hybridization occurred surreptitiously or intentionally, which of course would suggest that early framers knew something about the benefits of cross-breeding.

From H. Michael Kubisch.

Undoing millennia of barley selection

Generations of beer-loving farmers have bred seed dormancy almost entirely out of barley, so that the grains will readily germinate in the malthouse. Unfortunately, that means that malting varieties are sometimes prone to jumping the gun and sprouting before harvest, while the crop is still standing in the field. That means that the grain cannot be used to make beer. Not a good thing.

Fortunately, a PhD student in Australia, a land well known for its love of the amber nectar, has compared the barley genome with that of Arabidopsis and identified some bits which may contain previously unknown dormancy genes. Should a negative effect on pre-harvest sprouting be confirmed in the field – and trials are under way – breeders could use markers for these genes to help them select genotypes which will only sprout where it would do the most good: in the maltings.

Durum wheat erosion

If there’s a dominant meta-narrative in agricultural biodiversity circles it is that modern breeding programmes relentlessly decrease the genetic diversity of crops, increasing yields and quality but also, as new varieties displace landraces and older varieties in farmers’ fields, depleting the very resource on which they are dependent for continued success. But actually there’s not really that much in the way of hard figures on this process. So a recent paper on what breeding has done to diversity in Italian durum wheat is very much to be welcomed.

The researchers used molecular and biochemical markers to compare genetic diversity among five different groups of durum varieties, ranging from landraces from before 1915, to pure lines derived from landraces in the 30s, to genotypes selected from crosses between local material and CIMMYT lines in the 70s. In general, there was indeed a narrowing of the genetic diversity within these groups over time. In fact, the degree of narrowing was probably underestimated, because only a relatively few of the pre-1915 landraces were still available for analysis. Conserving what is left is all the more important.

Alternative livelihoods

Do wander over to the latest edition of New Agriculturist, which, among other things, has a great feature giving examples of farmers adopting new crops and other ways of making a living as alternatives to illicit, environmentally damaging or otherwise inappropriate ones.

Rice in Italy

40869585_bdcd1db3d8_b.jpg No, not Condy Rice seeing the sights: rice the crop, and its future in Italy. It may surprise some people that rice is grown in Italy, but it has a long history of cultivation in the Po Valley, and an important place in the local cuisine, as anyone who has eaten risotto will testify. Unfortunately, the ongoing drought in the region is causing severe problems for thousands of rice farmers (among others) in the Val Padana. Some people are saying that’s the shape of things to come, with climate change and all. But here’s an interesting juxtaposition of news: it’s been announced that the Slow Food Foundation for Diversity, based in Tuscany, is to start marketing in Europe a traditional, organically grown, Filipino rice known as “unoy.” Isn’t globalization wonderful?

Photo from ciordia9 on Flickr provided under a Creative Commons license.